dumpstate: save background traces when a BR is captured.
Adds a call to perfetto --save-for-bugreport to bugreport.
If a background trace labeled with bugreport_score > 0 is
being recorded when dumpstate is invoked, the tracing daemon
will stop the trace and serialize it into a fixed location
(/data/misc/perfetto-traces/bugreport/systrace.pftrace).
If no background tracing is happening, the command is a no-op.
The trace saving happens in two stages:
1. In the very early stage of dumpstate, the trace is
snapshoted (if in progress). This prevents that further
dumpstate activity pushes out interesting contents from
the trace buffer.
2. In the later stages of dumpstate, the trace is attached
to the bugreport.zip file and cleaned up.
Bug: 170334305
Change-Id: I4278459697a5ed20b20ee99032884874a82a66be
diff --git a/cmds/dumpstate/DumpstateUtil.cpp b/cmds/dumpstate/DumpstateUtil.cpp
index eeaa5a3..c833d0e 100644
--- a/cmds/dumpstate/DumpstateUtil.cpp
+++ b/cmds/dumpstate/DumpstateUtil.cpp
@@ -124,6 +124,12 @@
return *this;
}
+CommandOptions::CommandOptionsBuilder&
+CommandOptions::CommandOptionsBuilder::CloseAllFileDescriptorsOnExec() {
+ values.close_all_fds_on_exec_ = true;
+ return *this;
+}
+
CommandOptions::CommandOptionsBuilder& CommandOptions::CommandOptionsBuilder::Log(
const std::string& message) {
values.logging_message_ = message;
@@ -137,6 +143,7 @@
CommandOptions::CommandOptionsValues::CommandOptionsValues(int64_t timeout_ms)
: timeout_ms_(timeout_ms),
always_(false),
+ close_all_fds_on_exec_(false),
account_mode_(DONT_DROP_ROOT),
output_mode_(NORMAL_OUTPUT),
logging_message_("") {
@@ -157,6 +164,10 @@
return values.always_;
}
+bool CommandOptions::ShouldCloseAllFileDescriptorsOnExec() const {
+ return values.close_all_fds_on_exec_;
+}
+
PrivilegeMode CommandOptions::PrivilegeMode() const {
return values.account_mode_;
}
@@ -277,7 +288,8 @@
MYLOGI(logging_message.c_str(), command_string.c_str());
}
- bool silent = (options.OutputMode() == REDIRECT_TO_STDERR);
+ bool silent = (options.OutputMode() == REDIRECT_TO_STDERR ||
+ options.ShouldCloseAllFileDescriptorsOnExec());
bool redirecting_to_fd = STDOUT_FILENO != fd;
if (PropertiesHelper::IsDryRun() && !options.Always()) {
@@ -314,7 +326,27 @@
return -1;
}
- if (silent) {
+ if (options.ShouldCloseAllFileDescriptorsOnExec()) {
+ int devnull_fd = TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));
+ TEMP_FAILURE_RETRY(dup2(devnull_fd, STDIN_FILENO));
+ close(devnull_fd);
+ devnull_fd = TEMP_FAILURE_RETRY(open("/dev/null", O_WRONLY));
+ TEMP_FAILURE_RETRY(dup2(devnull_fd, STDOUT_FILENO));
+ TEMP_FAILURE_RETRY(dup2(devnull_fd, STDERR_FILENO));
+ close(devnull_fd);
+ // This is to avoid leaking FDs that, accidentally, have not been
+ // marked as O_CLOEXEC. Leaking FDs across exec can cause failures
+ // when execing a process that has a SELinux auto_trans rule.
+ // Here we assume that the dumpstate process didn't open more than
+ // 1000 FDs. In theory we could iterate through /proc/self/fd/, but
+ // doing that in a fork-safe way is too complex and not worth it
+ // (opendir()/readdir() do heap allocations and take locks).
+ for (int i = 0; i < 1000; i++) {
+ if (i != STDIN_FILENO && i!= STDOUT_FILENO && i != STDERR_FILENO) {
+ close(i);
+ }
+ }
+ } else if (silent) {
// Redirects stdout to stderr
TEMP_FAILURE_RETRY(dup2(STDERR_FILENO, STDOUT_FILENO));
} else if (redirecting_to_fd) {